Condenser electrode terminal



Oct. 15, J BROCK CONDENSER ELECTRODE TERMINAL Filed April 14, 1958 INVENTOR Jamzs 7F Brar/f 2 ATTORNEY PatentedOct.15,1v94O V- 2,218,162

UNITED STATES PATENT OFFICE I CONDENSER ELECTRODE TERMINAL James It. Brock, Indianapolis, Ind.,' assignor to P. R. Mallory & 00., Inc., Indianapolis, 11111., a corporation of Delaware Application April 14, 1938, Serial No. 201,863

1 Claim. (Cl. 175-315) This invention relates to terminals for the elecone-half inch wide and several inches long and trodes of electric condensers. a few mils thick. In some cases it will be desir- An object of the invention is to improve the able to prepare the surface of the foil by etching terminal construction for electric condenser elecor other roughening processes to subsequently 5 trodes, particularly for electrodes of electrolytic enable better bonding to the condenser electrode. 5 condensers. In forming the terminal, one end of metal strip Other objects of the invention will be apparent In is inserted in a slot IS in a block I! and laterfrom the following description and accompanying ally compressing the strip by a flat slide l3 which drawing taken in connection with the appended presses against one edge of the strip as shown in 1 ,1 Figures 2, 3 and 4. As slide l3 compresses the end 10 The invention comprises the features of conof strip it it forms a series of longitudinal ribs struction, combination of elements, arrangement therein which are further compressed together of parts, and methods of manufacture and operuntil a solid compact section is formed having ation referred to above or which will be brought a series of longitudinal folds 14 therein, as shown 15 out and exemplified in the disclosure hereinafter in Figure 4, for example. The free end of strip 5 set forth, including the illustrations in the drawill remains as it was origin y and a series of diing, verging ribs l5 form naturally in the region be- In the drawing: tween the compressed end and the free end as Figure 1 is a perspective view of a piece of shown in Figure 4. These ribs 15 serve to sheet metal stock for use in producing a terminal strengthen this region. 20 according to the present invention. Figure 5 shows the completed terminal member Figures 2, 3 and 4 show parts of the apparatus comprising the flat section ll corresponding to and process for forming the terminal; the original strip and the compressed end ll Figure 5 shows a completed terminal; which is of considerably greater thickness than Figure 6 shows a terminal attached to a conthe original strip and also of greater strength. 25 denser electrode; The section II will have an almost rectangular Figure '7 shows a modified terminal electrode cross-section and the folds ll therein will be arrangement; almost unnoticeable if the pressure used in com- Flgure 8 shows another form of electrode atpressing the end is suillcient. The compressed tached to another terminal; and end II will also become strain-hardened to some Figure 9 shows a further form. extent by the compressing operation. This may According to a preferred means of carrying be an advantage in some cases. If, however, the out the invention the electrode terminal is formed original softness of the metal is desired it may from a strip of relatively thin sheet stock, a pen readily be annealed by simply passing the tertion of which is compressed together to form a minal ll momentarily through a gas flame. 35 part of greater thickness and mechanical Figure 6 shows the terminal i0 attached to a strength. The invention is applicable to termifoil electrode ill by placing the thin flat portion nals for the electrodes of electric condensers genll of the terminal a a t the electrode foil l8 erally, and is particularly suitable for terminals and punching several holes l9 therethrough and for the electrodes of dry electrolytic condensers. then meshing down the burrs produced by the 40 While a preferred embodiment of the invenpunching operation. tion is described herein, it is contemplated that It will be noted that the diverging ribs l5 are considerable variation may be made in the methlocated just beyond the edge of the electrode l8 od of procedure and the construction of parts thereby serving to strengthen the terminal memwithout departing from the spirit of the invenher in the region where the greatest strain is ap- 45 tion. In the following description and in the plied to it. claim, parts will be identified by specific names Figure 7 shows a modification wherein the terfor convenience, but they are intended to be as minal portion 2| is formed directly from the foil generic in their application to similar parts as electrode 22 by cutting the tab at the end of the the art will permit. electrode foil strip and compressing the end of 50 Referring to the drawing, Figure 1 shows a thin the tab together to form a heavy securing porstrip of metal l0 suitable for use in producing tion 2| similar to the portion ll previously dethe terminal. If the terminal is to be used for scribed. dry electrolytic condensers, for example, the strip Figure 8 shows a modified form of terminal and Ill may comprise a strip of aluminum foil about how the terminal may be attached to an elec- 55 trode formed of metal sprayed onto a fibrous base, such as cloth or gauze. This terminal is similar to terminal ill of Figure 5 but has serrated or scalloped edges 20 formed in the portion ll.

According to this arrangement the serrated portion I! of terminal III is inserted between two strips of gauze 23 and 24, after which a suitable electrode metal such as aluminum is sprayed onto both gauze layers by a metal spray gun. The sprayed metal penetrates through the gauze to some extent, provided it-is sufllciently openmesh, thereby bonding the two layers of gauze together and bonding the electrode terminal between them. For this form of electrode, it is preferred that the surface of the terminal ll be etched or otherwise roughened so that the sprayed metal will adhere to it.

Due to the scallops or serrations in its edges the portion I! of the terminal will flex more readily with the electrode when it is wound into a condenser assembly and will distribute the bending over a wider region. Hence no straight line edge will be present where cracking or straining of the electrode or its connection to the terminal can occur. The irregular edge also gives a greater contact area between the edge of the tab and the anode, decreasing current concentration.

Figure 9 shows another form of assembly in which a terminal member 30 is used similar to terminal l0 except that both of its ends are compressed together as previously described to form terminal portions 3| and 32. This terminal may be utilized by inserting it between two gauze layers 33 and 34, as shown in Figure 9, and spraying the two layers with electrode metal as previously described. The resulting electrode terminal member will then have terminals projecting from both edges. It may be cut in two along the center line 35 to form two similar electrodes. If desired the terminal 30 may be secured to one of the gauze layers 34 by punching before the spraydeposit is applied.

The terminal portion II, II or II of the electrode terminal may be used as a connecting terminal for the electrode in any one of several wellknown manners. For example, the terminal portion may be passed through an aperture in the top of the condenser container and clamped to a soldering lug.

The terminal element produced according to this invention has the advantage of providing a thinner and more flexible portion !or connection between the terminal member and the electrode and a thicker, stii'fer portion for connection between the terminal member and outside connecting means. The mid-portion where the diverging ribs appear is also strengthened by these ribs to reduce the possibility of the tab tearing at this point. The surface of the tab can be prepared in advance by etching or other processing toglve the desired connecting surface.

While the present invention, as to its objects and advantages, has been described herein as carried out in specific embodiments thereof, it is not desired to be limited thereby but it is intended to cover the invention broadly within the spirit and scope of the appended claim.

What is claimed is:

A dry electrolytic condenser electrode-terminal assembly comprising an electrode sheet formed of a fibrous layer having a deposit of film-forming metal thereon and a terminal therefor comprising a strip of sheet metal laid flat against said electrode sheet and bonded thereto by said metal deposit, said terminal strip having serrated edges in the region bonded to said electrode sheet, the teeth of said serrated edges lying in substantially the same plane as the body of said terminal strip when said assembly is laid flat, and rendering said terminal strip more readily flexible with said electrode sheet during winding of said condenser.

J AIMES R. BROOK. 

